public class Solution3 {
    public int minCostClimbingStairs(int[] cost) {
        int n = cost.length;
        if(n == 0 || n == 1) {
            return 0;
        }
        int[] dp = new int[n + 1];
        dp[0] = 0;
        dp[1] = 0;
        for(int i = 2; i <= n; i++) {
            dp[i] = Math.min(dp[i - 1] + cost[i - 1] , dp[i - 2] + cost[i - 2]);
        }
        return dp[n];
    }

    public int minCostClimbingStairs2(int[] cost) {
        int n = cost.length;
        if(n == 0 || n == 1) {
            return 0;
        }
        int[] dp = new int[n];
        dp[n - 1] = cost[n - 1];
        dp[n - 2] = cost[n - 2];
        for(int i = n - 3; i >= 0; i--) {
            dp[i] = Math.min(dp[i + 1] , dp[i + 2]) + cost[i];
        }
        return Math.min(dp[0], dp[1]);
    }
}
